EP2570450A1 - Shape memory material based on a structural adhesive - Google Patents

Abstract

Composition comprises at least one curable structural adhesive and at least one chemically crosslinked elastomer based on a silane-functional polymer. Independent claims are also included for: (1) producing the composition, comprising mixing the curable structural adhesive with the silane-functional polymer, and cross-linking the silane-functional polymer in the blend to form an elastomer; (2) molded body (3), which has undergone a reversible molding, comprising (i) heating the composition to a temperature above its glass transition temperature, (ii) deforming the composition under tension of the chemically crosslinked elastomer based on the silane-functional polymer, and cooling the molded composition to its glass transition temperature; and (3) a reinforcing element for reinforcing in hollow spaces (10) of structural components (6), comprising a support (5), on which the molded body is mounted.

Description

Technical area

The invention is in the field of compositions comprising curable structural adhesives, which are designed as so-called shape memory materials. Furthermore, the invention relates to a reinforcing element for reinforcement in cavities of structural components, such as those used in automobile bodies and the like.

State of the art

Often hollow structures are used in structures of any kind. This design makes it possible to keep the weight of the construction and the cost of materials low, but are often lost in this design, stability and strength. The cavities also offer, due to the larger surface of the hollow component, a larger surface for corrosion if moisture or dirt penetrates into it. Also, noise caused by, for example, wind or vibration may be transmitted in or along the cavities.

Due to the shape and / or the narrow dimensions of such cavities, it is often difficult to efficiently reinforce, seal or curb noise transmission.

In particular, in order to improve the mechanical properties of hollow structural components, it is common practice to use local reinforcing elements in the components or to install. Such reinforcing elements are typically made of metals or plastics or combinations of these materials. In hard to reach places, which are to be reinforced or sealed, for example, only after the assembly of the component, structural foams are often used. This is the case, for example, in the production of vehicle structures or bodies. The advantage of the structural foams is that they can be mounted in a non-expanded state in a cavity and later foamed, especially by increasing the temperature can be. Thus, for example, the inner wall of the cavity can be completely coated even after the assembly of the reinforcing element by means of cathodic dip painting (KTL) and only then be reinforced by foaming of the structural adhesive. The foaming typically takes place during the hardening of the cathodic electrocoating layer in the oven.

The disadvantage of such reinforcing elements is that the mechanical properties of the structural adhesive are adversely affected by the foaming process.

Presentation of the invention

The object of the present invention is therefore to provide a reinforcing element which overcomes the disadvantages of the prior art and makes it possible, for example, to close a gap between the cavity and the reinforcing element without impairing the mechanical properties of the structural adhesive.

Surprisingly, it has been found that with compositions according to claim 1, this object can be achieved.

It has been found that shape-memory materials can be realized with compositions according to the invention which change their shape in particular as a result of the influence of temperature and thus expand in a desired direction, without causing an increase in volume, for example by a foaming process.

Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims.

Brief description of the drawings

Reference to the drawings embodiments of the invention will be explained in more detail. Same elements are in the different figures with the same Provided with reference numerals. Of course, the invention is not limited to the illustrated and described embodiments.

Figur 1

eine schematische Darstellung der Herstellung eines Formkörpers bzw. einer Zusammensetzung in ihrer temporären Form;

Figur 2

eine schematische Darstellung Verstärkungselements;

Figur 3

eine schematische Darstellung der Formänderung und Aushärtung der Zusammensetzung;

Figur 4

eine schematische Darstellung der Verstärkung eines Hohlraums eines strukturellen Bauteils;

Figur 5

eine schematische Darstellung eines Verstärkungselements in einem Hohlraum eines strukturellen Bauteils;

Figur 6

eine schematische Darstellung eines verstärkten strukturellen Bauteils.

Show it:

FIG. 1

a schematic representation of the preparation of a shaped body or a composition in its temporary form;

FIG. 2

a schematic representation of reinforcing element;

FIG. 3

a schematic representation of the change in shape and curing of the composition;

FIG. 4

a schematic representation of the reinforcement of a cavity of a structural component;

FIG. 5

a schematic representation of a reinforcing element in a cavity of a structural component;

FIG. 6

a schematic representation of a reinforced structural component.

In the figures, only the elements essential for the immediate understanding of the invention are shown.

Ways to carry out the invention

• mindestens einen härtbaren Strukturklebstoff; sowie
• mindestens ein chemisch vernetztes Elastomer auf der Basis eines silanfunktionellen Polymers.

The present invention relates, in a first aspect, to a composition comprising

• at least one curable structural adhesive; such as
• at least one chemically cross-linked elastomer based on a silane-functional polymer.

The chemically crosslinked elastomer is preferably present as a penetrating polymer network in the structural adhesive.

Substance names beginning with "poly", such as polyol or polyisocyanate, in the present document refer to substances which formally contain two or more of the functional groups occurring in their name per molecule. The term "polymer" in the present document comprises, on the one hand, a collective of chemically uniform, but with respect to degree of polymerization, Molecular mass and chain length differing macromolecules, which was prepared by a polyreaction (polymerization, polyaddition, polycondensation). On the other hand, the term also encompasses derivatives of such a collective of macromolecules from polyreactions, compounds which have been obtained by reactions, such as additions or substitutions, of functional groups on given macromolecules and which may be chemically uniform or chemically nonuniform. The term also includes so-called prepolymers, ie reactive oligomeric pre-adducts whose functional groups are involved in the construction of macromolecules. The term "polyurethane polymer" includes all polymers which are prepared by the so-called diisocyanate polyaddition process. This also includes those polymers which are almost or completely free of urethane groups. Examples of polyurethane polymers are polyether-polyurethanes, polyester-polyurethanes, polyether-polyureas, polyureas, polyester-polyureas, polyisocyanurates and polycarbodiimides.

In the present document, the terms "silane" and "organosilane" refer to compounds which have on the one hand at least one, usually two or three, via Si-O bonds, alkoxy groups or acyloxy groups bonded directly to the silicon atom, and at least one, via a Si-C bond, directly to the silicon atom bonded organic radical. Such silanes are also known to the person skilled in the art as organoalkoxysilanes or organoacyloxysilanes.

Similarly, the term "silane group" refers to the silicon-containing group attached to the organic group of the silane bonded through the Si-C bond. The silanes, or their silane groups, have the property of hydrolyzing on contact with moisture. In this case, organosilanols, that is, organosilicon compounds containing one or more silanol groups (Si-OH groups) and, by subsequent condensation reactions, organosiloxanes, that is, organosiloxane compounds containing one or more siloxane groups (Si-O-Si groups). The term "silane-functional" refers to compounds having silane groups. "Silane-functional polymers" are accordingly polymers which have at least one silane group.

As "aminosilanes" or "mercaptosilanes" organosilanes are referred to, the organic radical having an amino group or a mercapto group. As "primary aminosilanes" aminosilanes are referred to which have a primary amino group, ie an NH ₂ group which is bonded to an organic radical. As "secondary aminosilanes" aminosilanes are referred to which have a secondary amino group, ie an NH group which is bonded to two organic radicals.

By "molecular weight" is meant in this document always the molecular weight average M _n (number average).

The term "penetrating polymer network" is used in the present document based on the definition of a " Semi-interpenetrating polymer network (SIPN) according to IUPAC Compendium of Chemical Terminology, 2nd Edition (1997 ) used. Accordingly, the SIPN comprises at least one network and at least one linear or branched polymer, which polymer at least partially penetrates the network. In the inventive composition, the elastomer forms the network, the polymer is part of the curable structural adhesive.

As "chemically crosslinked elastomer" is understood in the present document an elastomer which is crosslinked via covalent chemical bonds. In contrast, the crosslinking of a thermoplastic elastomer is based on physical interactions. A chemically crosslinked elastomer differs from a thermoplastic elastomer in that it swells in a suitable solvent but is not dissolved. On the other hand, a thermoplastic elastomer dissolves completely in a suitable solvent.

The presence of a chemically crosslinked elastomer can be determined, for example, on the basis of ASTM D 2765.

The glass transition temperature Tg of a composition in the present document is understood as meaning the glass transition temperature of the curable structural adhesive, that is to say in particular of the epoxy resin A , or the glass transition temperature of the chemically crosslinked elastomer, depending on which of the two is higher. In embodiments with a curable structural adhesive based on an epoxy solid resin, the glass transition temperature Tg of the composition usually refers to the glass transition temperature Tg of the epoxy solid resin. In embodiments with a curable structural adhesive based on an epoxy liquid resin, the glass transition temperature Tg of the composition generally refers to the glass transition temperature Tg of the chemically crosslinked elastomer.

The glass transition temperature Tg and melting points are typically measured by DSC (Differential Scanning Calorimetry), with measurements taken on a Mettler Toledo 822e instrument at a heating rate of 10 ° C / min to 180 ° C on 5 mg samples. The measured values are determined using the DSC software from the measured DSC curve.

The composition according to the invention, which constitutes a "shape memory material", can be brought into a specific shape ("original shape") during its production or processing and, after this shaping, has a solid consistency, that is to say in that the composition is at a temperature below its glass transition temperature Tg. In this form, the chemically crosslinked elastomer, which is present in particular as a penetrating polymer network in the structural adhesive, is substantially relaxed before. If necessary, the composition is then heated to a temperature above its glass transition temperature Tg and placed in any shape ("temporary shape"). In this temporary form, the chemically crosslinked elastomer is in a taut form. The composition is maintained in this temporary form and the temperature of the composition is lowered below its glass transition temperature Tg again, whereby the composition solidifies in the temporary mold. In this temporary form, the composition is storage-stable and can be subjected to processing, for example stamping or cutting. If the composition is reheated at a later time to a temperature which is above its glass transition temperature Tg, the elastomer returns to its relaxed form and thus deforms the entire composition to its original shape.

Thus, the present invention also relates to a shape memory material comprising a composition according to the invention.

In particular, the composition according to the invention is a shape-memory material which is solid at room temperature (23 ° C.), which allows optimum handling of the material in its original and temporary form.

In order for the composition according to the invention to be solid at room temperature, it should have a glass transition temperature Tg, which is above room temperature. Otherwise, the composition according to the invention, after being brought into its temporary form, could not keep the elastomer, which is tensed in this temporary form, in this form at room temperature.

Preferably, the composition of the invention has a glass transition temperature Tg in the range of 23 ° C to 95 ° C, in particular from 30 ° C to 80 ° C, preferably from 35 ° C to 75 ° C, on.

Further preferably, the surface of the inventive composition is not tacky at room temperature, which facilitates their handling.

The curable structural adhesive is in particular a heat-curing structural adhesive which preferably has a curing temperature in the range from 120 ° C. to 220 ° C., in particular from 160 ° C. to 200 ° C.

When the curable structural adhesive is a thermoset structural adhesive, care must be taken during processing of the composition to bring it into its temporary shape so that the composition does not heat enough to begin the curing process.

Most preferably, the curable structural adhesive is an epoxy resin composition comprising at least one epoxy resin A and at least one curing agent B for epoxy resins, which is activated by elevated temperature. In particular, it is a one-component epoxy resin composition.

The epoxy resin A , has on average more than one epoxy group per molecule and is in particular a solid epoxy resin or a mixture of a solid epoxy resin with an epoxy liquid resin. The term "solid epoxy resin" is well known to the person skilled in the epoxy art and is used in contrast to "liquid epoxy resin". The glass transition temperature Tg of solid resins is above room temperature.

Preferred solid epoxy resins have the formula (I).

Here, the substituents R ¹ and R ² independently of one another are either H or CH ₃ . Furthermore, the index s stands for a value of ≥ 1, in particular of ≥ 1.5, preferably of 2 to 12.

Preferred solid epoxy resins have a glass transition temperature Tg in the range of 23 ° C to 95 ° C, in particular from 30 ° C to 80 ° C, preferably from 35 ° C to 75 ° C, on.

Such solid epoxy resins are, for example, commercially available from Dow Chemical Company, USA, from Huntsman International LLC, USA, or from Hexion Specialty Chemicals Inc, USA.

Preferred liquid epoxy resins, which can be used in particular together with a solid epoxy resin, have the formula (II).

Here, the substituents R ¹ and R ^{2 are} again, independently of one another, either H or CH ₃ . Furthermore, the index r stands for a value from 0 to 1. Preferably, r stands for a value of ≦ 0.2.

Thus, it is preferably diglycidyl ethers of bisphenol-A (DGEBA), bisphenol-F and bisphenol-A / F. The term "A / F" refers to a mixture of acetone with formaldehyde, which is used as starting material in its preparation. Such liquid resins are available, for example under the trade names Araldite ^® GY 250, Araldite ^® PY 304, Araldite ^® GY 282 from Huntsman International LLC, USA, or DER ^® 331 or DER ^® 330 from Dow Chemical Company, USA, or under the trade name Epikote ^® 828 or Epikote ^® 862 from Hexion Specialty Chemicals Inc, USA, are commercially available.

Depending on the embodiment, the epoxy resin, which is used as one of the starting compounds in curable structural adhesive, may also be an epoxy liquid resin.

Other suitable epoxy resins are so-called novolacs. These have in particular the following formula (III).

In this case, the radical X is a hydrogen atom or a methyl group. The radical Y is -CH ₂ - or a radical of the formula (IV).

Furthermore, the index z stands for a value from 0 to 7, in particular for a value of ≥ 3.

In particular, these are phenol or cresol novolacs (Y is -CH 2 -).

Epoxy resins are sold under the trade names EPN or ECN and Tactix ^® 556 from Huntsman International, LLC, United States, or through the product series DEN ™ from Dow Chemical Company, USA, commercially available.

Preferably, the epoxy resin A is a solid epoxy resin of the formula (I). In another preferred embodiment, the thermosetting epoxy resin composition contains at least one solid epoxy resin of formula (I) and at least one liquid epoxy resin of formula (II).

The proportion of epoxy resin A is preferably 2 to 90 wt .-%, in particular 5 to 70 wt .-%, preferably 10 to 60 wt .-%, based on the total weight of the curable structural adhesive.

Hardener B for epoxy resins is activated by increased temperature. Hardener B is preferably a hardener selected from the group consisting of dicyandiamide, guanamine, guanidines, aminoguanidines and derivatives thereof; substituted ureas, in particular 3- (3-chloro-4-methylphenyl) -1, 1-dimethylurea (chlorotoluron), or phenyl-dimethylureas, in particular p-chlorophenyl-N, N-dimethylurea (monuron), 3-phenyl-1, 1-dimethylurea (fenuron), 3,4-dichlorophenyl-N, N-dimethylurea (diuron), as well as imidazoles and amine complexes.

Particularly preferred as hardener B is dicyandiamide, in particular in combination with a substituted urea. The advantage of combining dicyandiamide with a substituted urea is the accelerated cure of the composition achieved thereby.

The proportion of the curing agent B is preferably 0.05 to 8 wt .-%, in particular 0.1 to 6 wt .-%, preferably 0.2 to 5 wt .-%, based on the total weight of the curable structural adhesive.

The term "hardener" in the present document also includes catalysts and catalytically active compounds. The skilled person is in this Event that is clearly the use of a catalyst or a catalytically active compound as the curing agent B, the proportion of hardener B on total curable structural adhesive in the lower region of the specified range of values.

In addition, the epoxy resin composition may comprise at least one impact modifier.

By an "impact modifier" is meant in this document an addition of an organic polymer to an epoxy resin matrix which is already present in minor amounts, i. typically between 0.1 and 20% by weight with respect to the curable structural adhesive, causes a significant increase in toughness, and is thus able to absorb higher impact stress before the matrix breaks or breaks.

Suitable impact modifiers are, in particular, reactive liquid rubbers based on nitrile rubber or derivatives of polyetherpolyol-polyurethanes, core-shell polymers and similar systems known to the person skilled in the art.

Suitable impact modifiers are described as impact modifiers D in the European patent application with the application number EP08168009.2 , the contents of which are hereby incorporated by reference.

The curable structural adhesive may contain other ingredients commonly used in curable structural adhesives.

In particular, the curable structural adhesive additionally contains at least one filler. These are preferably mica, talc, kaolin, wollastonite, feldspar, syenite, chlorite, bentonite, montmorillonite, calcium carbonate (precipitated or ground), dolomite, quartz, silicic acids (pyrogenic or precipitated), cristobalite, calcium oxide, aluminum hydroxide, magnesium oxide, Ceramic hollow spheres, glass hollow spheres, organic hollow spheres, glass spheres, color pigments. Filler means both the organic coated and the uncoated commercially available and known in the art forms. Another example is functionalized alumoxanes, as z. In US 6,322,890 are described and the contents of which are hereby incorporated by reference.

Advantageously, the proportion of the filler is 1 to 60 wt .-%, preferably 5 to 50 wt .-%, in particular 10 to 35 wt .-%, based on the weight of the total curable structural adhesive.

As further constituents, the curable structural adhesive comprises, in particular, thixotropic agents such as, for example, aerosils or nanoclays, toughness modifiers, reactive diluents and other constituents known to the person skilled in the art.

Typically, the composition of the invention does not contain a chemical blowing agent or otherwise an agent which results in foaming of the composition.

Most preferably, the curable structural adhesive is a one-component, thermosetting epoxy resin composition.

The proportion of the curable structural adhesive is preferably 50 to 95 wt .-%, in particular 65 to 90 wt .-%, preferably 70 to 80 wt .-%, based on the total composition.

The composition according to the invention comprises at least one chemically cross-linked elastomer based on a silane-functional polymer. The chemically crosslinked elastomer is preferably present as a penetrating polymer network in the structural adhesive.

The chemically crosslinked elastomer based on a silane-functional polymer is introduced into the composition by mixing a silane-functional polymer with the curable structural adhesive and then crosslinking it in the mixture, so that in particular a penetrating polymer network is formed in the structural adhesive.

The proportion of the chemically crosslinked elastomer based on a silane-functional polymer is preferably 5 to 50 wt .-%, in particular 10 to 35 wt .-%, preferably 20 to 30 wt .-%, based on the total composition.

In particular, a silane-functional polymer P , which typically has end groups of the formula (V), are suitable as the silane-functional polymer.

In this case, the radical R ^{3 is} a linear or branched, monovalent hydrocarbon radical having 1 to 8 C atoms, in particular a methyl or ethyl group.

The radical R ⁴ is a linear or branched, divalent hydrocarbon radical having 1 to 12 C atoms, which optionally has cyclic and / or aromatic moieties, and optionally one or more heteroatoms, in particular one or more nitrogen atoms. In particular, R ^{4 is} a linear or branched alkylene group having 1 to 6 C atoms, preferably methylene or 1,3-propylene, particularly preferably 1,3-propylene.

The radical R ⁵ is an acyl radical or a linear or branched, monovalent hydrocarbon radical having 1 to 5 C atoms, in particular a methyl, ethyl or isopropyl group.

The index a stands for a value of 0 or 1 or 2, in particular for a value of 0.

Within a silane group of the formula (V), R ³ and R ^{5 are} each independently of one another the radicals described. Thus, for example, compounds having end groups of the formula (V) which are ethoxydimethoxysilane end groups (R ⁵ = methyl, R ⁵ = methyl, R ⁵ = ethyl) are also possible.

In a first embodiment, the silane-functional polymer P is a silane-functional polyurethane polymer P1 obtainable by reacting a silane having at least one isocyanate-reactive group with a polyurethane polymer having isocyanate groups. This reaction is preferably carried out in a stoichiometric ratio of the isocyanate-reactive groups to the isocyanate groups of 1: 1 or with a slight excess of isocyanate-reactive groups, so that the resulting silane-functional polyurethane polymer P1 is completely free from isocyanate groups. In the reaction of the silane, which has at least one isocyanate-reactive group, with a polyurethane polymer having isocyanate groups, the silane may in principle, although not preferred, be used substoichiometrically, so that a silane-functional polymer is obtained which contains both silane groups Has isocyanate groups.

The silane which has at least one isocyanate-reactive group is, in particular, a mercaptosilane or an aminosilane, preferably an aminosilane.

wobei R³, R⁴, R⁵ und a bereits vorhergehend beschrieben worden sind und R⁷ für ein Wasserstoffatom oder für einen linearen oder verzweigten, einwertigen Kohlenwasserstoffrest mit 1 bis 20 C-Atomen, welcher gegebenenfalls cyclische Anteile aufweist, oder für einen Rest der Formel (VII) steht.

The aminosilane is preferably an aminosilane AS of the formula (VI)

wherein R ³ , R ⁴ , R ⁵ and a have already been described above and R ^{7 is} a hydrogen atom or a linear or branched, monovalent hydrocarbon radical having 1 to 20 C-atoms, which optionally has cyclic moieties, or a radical of Formula (VII) stands.

The radicals R ⁸ and R ^{9 are} each independently of one another a hydrogen atom or a radical from the group consisting of -R ¹¹ , -COOR "and -CN.

The radical R ¹⁰ is a hydrogen atom or a radical from the group consisting of -CH ₂ -COOR ¹¹ , -COOR ¹¹ , -CONHR ¹¹ , -CON (R ¹¹ ) ₂ , -CN, -NO ₂ , -PO ( OR ¹¹ ) ₂ , -SO ₂ R ¹¹ and -SO ₂ OR ¹¹ .

The radical R ¹¹ is a, optionally having at least one heteroatom, hydrocarbon radical having 1 to 20 carbon atoms.

Examples of suitable aminosilanes AS are primary aminosilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane; secondary aminosilanes such as N-butyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane; the products of Michael-type addition of primary aminosilanes such as 3-aminopropyltrimethoxysilane or 3-aminopropyldimethoxymethylsilane to Michael acceptors such as acrylonitrile, (meth) acrylic acid esters, (meth) acrylic acid amides, maleic and fumaric diesters, citraconic diesters and itaconic diesters, for example N- (3 Trimethoxysilyl-propyl) -amino-succinic acid dimethyl and diethyl ester; and analogs of said aminosilanes having ethoxy or isopropoxy groups in place of the methoxy groups on the silicon. Particularly suitable aminosilanes AS are secondary aminosilanes, in particular aminosilanes AS , in which R ⁷ in formula (VI) is different from H. Preference is given to the Michael-type adducts, in particular N- (3-trimethoxysilyl-propyl) -amino-succinic acid diethyl ester.

The term "Michael acceptor" in the present document denotes compounds which, owing to the double bonds which are activated by electron acceptor radicals, are capable of undergoing nucleophilic addition reactions with primary amino groups in a manner analogous to Michael addition (hetero-Michael addition). ,

Suitable polyurethane polymers having isocyanate groups for preparing a silane-functional polyurethane polymer P1 are, for example, polymers, which are obtainable by the reaction of at least one polyol with at least one polyisocyanate, in particular a diisocyanate. This reaction can be carried out by reacting the polyol and the polyisocyanate with customary processes, for example at from 50 ° C. to 100 ° C., if appropriate with concomitant use of suitable catalysts, the polyisocyanate being metered in such a way that its isocyanate groups in the Ratio to the hydroxyl groups of the polyol in stoichiometric excess are present.

In particular, the excess of polyisocyanate is chosen so that in the resulting polyurethane polymer after the reaction of all hydroxyl groups of the polyol, a content of free isocyanate groups from 0.1 to 5 wt .-%, preferably 0.1 to 2.5 wt .-%, particularly preferably 0.2 to 1 wt. -%, based on the total polymer, remains.

Optionally, the polyurethane polymer can be prepared with the concomitant use of plasticizers, wherein the plasticizers used contain no isocyanate-reactive groups.

Preference is given to polyurethane polymers having the stated content of free isocyanate groups, which are obtained from the reaction of diisocyanates with high molecular weight diols in an NCO: OH ratio of 1.5: 1 to 2.2: 1.

Suitable polyols for the preparation of the polyurethane polymer are in particular polyether polyols, polyester polyols and polycarbonate polyols and mixtures of these polyols.

Suitable polyether polyols, also called polyoxyalkylene polyols or oligoetherols, are in particular those which are polymerization products of ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide, oxetane, tetrahydrofuran or mixtures thereof, optionally polymerized with the aid of a starter molecule with two or more active hydrogen atoms such as water, ammonia or compounds with multiple OH or NH groups such as 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and Tripropylene glycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1, 1-trimethylolpropane, glycerol, aniline, and mixtures of the compounds mentioned. Both polyoxyalkylene polyols having a low degree of unsaturation (measured according to ASTM D-2849-69 and expressed in milliequivalents of unsaturation per gram of polyol (mEq / g)) prepared, for example, by means of so-called double metal cyanide complex catalysts (DMC Catalysts), as well as polyoxyalkylene polyols having a higher degree of unsaturation, prepared for example with the aid of anionic catalysts such as NaOH, KOH, CsOH or alkali metal alkoxides.

Particularly suitable are polyoxyethylene polyols and polyoxypropylene polyols, in particular polyoxyethylene diols, polyoxypropylene diols, polyoxyethylene triols and polyoxypropylene triols.

Particularly suitable are polyoxyalkylenediols or polyoxyalkylenetriols having a degree of unsaturation lower than 0.02 meq / g and having a molecular weight in the range from 1000 to 30,000 g / mol, and polyoxyethylenediols, polyoxyethylenetriols, polyoxypropylenediols and polyoxypropylenetriols having a molecular weight of from 400 to 20,000 g / mol.

Also particularly suitable are so-called ethylene oxide-terminated ("EOendcapped", ethylene oxide-endcapped) polyoxypropylene polyols. The latter are specific polyoxypropylene polyoxyethylene polyols obtained, for example, by further alkoxylating pure polyoxypropylene polyols, especially polyoxypropylene diols and triols, upon completion of the polypropoxylation reaction with ethylene oxide, thereby having primary hydroxyl groups. Preferred in this case are polyoxypropylene polyoxyethylene diols and polyoxypropylene polyoxyethylene triols.

Also suitable are hydroxyl-terminated polybutadiene polyols, such as those prepared by polymerization of 1,3-butadiene and allyl alcohol or by oxidation of polybutadiene, and their hydrogenation products.

Also suitable are styrene-acrylonitrile grafted polyether polyols, such as are commercially available for example under the trade name Lupranol ^® by the company Elastogran GmbH, Germany.

Suitable polyester polyols are in particular polyesters which carry at least two hydroxyl groups and are prepared by known processes, in particular the polycondensation of hydroxycarboxylic acids or the polycondensation of aliphatic and / or aromatic polycarboxylic acids with dihydric or polyhydric alcohols.

Particularly suitable are polyester polyols which are prepared from bis-trihydric alcohols such as 1,2-ethanediol, diethylene glycol, 1,2-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, Glycerol, 1,1,1-trimethylolpropane or mixtures of the abovementioned alcohols with organic dicarboxylic acids or their anhydrides or esters such as succinic, glutaric, adipic, trimethyladipic, suberic, azelaic, sebacic, dodecanedicarboxylic, maleic, fumaric, dimer fatty, phthalic, phthalic, Isophthalic acid, terephthalic acid, dimethyl terephthalate, hexahydrophthalic acid, trimellitic acid and trimellitic anhydride or mixtures of the aforementioned acids, and polyester polyols from lactones such as ε-caprolactone.

Especially suitable are polyesterdiols, in particular those prepared from adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer fatty acid, phthalic acid, isophthalic acid and terephthalic acid as dicarboxylic acid or from lactones such as ε-caprolactone and from ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol , 1,6-hexanediol, dimer fatty acid diol and 1,4-cyclohexanedimethanol as the dihydric alcohol.

Suitable polycarbonate polyols are, in particular, those which are obtainable by reacting, for example, the abovementioned alcohols used for the synthesis of the polyester polyols with dialkyl carbonates, such as dimethyl carbonate, diaryl carbonates, such as diphenyl carbonate or phosgene. Particularly suitable are polycarbonate diols, in particular amorphous polycarbonate diols.

Further suitable polyols are poly (meth) acrylate polyols.

Also suitable are polyhydroxy-functional fats and oils, for example natural fats and oils, in particular castor oil, or so-called oleochemical polyols obtained by chemical modification of natural fats and oils, the epoxy polyesters obtained, for example, by epoxidation of unsaturated oils and subsequent ring opening with carboxylic acids or alcohols or epoxypolyethers, or obtained by hydroformylation and hydrogenation of unsaturated oils polyols. Also suitable are polyols which are obtained from natural fats and oils by degradation processes such as alcoholysis or ozonolysis and subsequent chemical linkage, for example by transesterification or dimerization, of the degradation products or derivatives thereof thus obtained. Suitable degradation products of natural fats and oils are in particular fatty acids and fatty alcohols and fatty acid esters, in particular the methyl esters (FAME), which can be derivatized for example by hydroformylation and hydrogenation to hydroxy fatty acid esters.

Likewise suitable are also polyhydrocarbon polyols, also called oligohydrocarbonols, for example polyhydroxy-functional ethylene-propylene, ethylene-butylene or ethylene-propylene-diene copolymers, as are produced, for example, by Kraton Polymers, USA, or polyhydroxy-functional copolymers of dienes, such as 1,3-butadiene or diene mixtures and vinyl monomers such as styrene, acrylonitrile or isobutylene, or polyhydroxy-functional polybutadiene polyols, for example those which are prepared by copolymerization of 1,3-butadiene and allyl alcohol and may also be hydrogenated.

Also suitable are Polyhydroxy-functional acrylonitrile / butadiene copolymers, as they can be prepared, for example, from epoxides or aminoalcohols and carboxyl-terminated acrylonitrile / butadiene copolymers, which are commercially available performance under the name Hypro ^® CTBN from the company Emerald Performance Materials, LLC, USA.

These stated polyols preferably have an average molecular weight of 250 to 30,000 g / mol, in particular of 1000 to 30,000 g / mol, and an average OH functionality in the range of 1.6 to 3.

Particularly suitable polyols are polyester polyols and polyether polyols, especially polyoxyethylene polyol, polyoxypropylene polyol and polyoxypropylene polyoxyethylene polyol, preferably polyoxyethylene diol, polyoxypropylene diol, polyoxyethylene triol, polyoxypropylene triol, polyoxypropylene polyoxyethylene diol and polyoxypropylene polyoxyethylene triol.

In addition to these mentioned polyols, small amounts of low molecular weight di- or polyhydric alcohols such as 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols, Pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, dimeric fatty alcohols, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, Pentaerythritol, sugar alcohols such as xylitol, sorbitol or mannitol, sugars such as sucrose, other higher alcohols, low molecular weight alkoxylation of the aforementioned dihydric and polyhydric alcohols, and mixtures of the aforementioned alcohols in the preparation of the terminal isocyanate group-containing polyurethane polymer are used.

To adjust the OH functionality of the polyols monohydric alcohols (monools) can be used, for example, butanol, 2-ethylhexanol or an alcohol-initiated polyoxyalkylene monool.

Commercially available polyisocyanates, in particular diisocyanates, can be used as polyisocyanates for the preparation of the polyurethane polymer. For example, suitable diisocyanates are 1,6-hexamethylene diisocyanate (HDI), 2-methylpentamethylene-1,5-diisocyanate, 2,2,4- and 2,4,4-trimethyl-1,6-hexamethylene diisocyanate (TMDI), 1,12-dodecamethylene diisocyanate, lysine and lysine ester diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (isophorone diisocyanate or IPDI), perhydro-2,4'-diphenylmethane diisocyanate and perhydro-4,4'-diphenylmethane diisocyanate, 1,4-diisocyanato-2,2,6-trimethylcyclohexane (TMCDI), 1,3- and 1,4-bis- (isocyanatomethyl) cyclohexane, m- and p-xylylene diisocyanate (m- and p-XDI), m- and p-tetramethyl-1,3-xylylene diisocyanate, m- and p-tetramethyl-1,4-xylylene diisocyanate, bis ( 1-isocyanato-1-methylethyl) -naphthalene, 2,4- and 2,6-toluene diisocyanate (TDI), 4,4'-, 2,4'- and 2,2'-diphenylmethane diisocyanate (MDI), 1,3 and 1,4-phenylene diisocyanate, 2,3,5,6-tetramethyl-1,4-diisocyanatobenzene, naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'-diisocyanatodiphenyl (TODI ), Oligomers and polymers of the aforementioned polyisocyanates, as well as any mixtures of the aforementioned polyisocyanates.

Particularly suitable polyisocyanates are HDI, TMDI, IPDI, TDI and MDI, in particular IPDI.

For example, suitable silane-functional polymers P1 are commercially available under the trade name Polymer ST, for example polymer ST50 from the company Hanse Chemie AG, Germany, and under the trade name Desmoseaf ^® from Bayer MaterialScience AG, Germany.

The silane-functional polymer P is, in a second embodiment, a silane-functional polyurethane polymer P2 obtainable by the reaction of an isocyanatosilane IS with a polymer which has isocyanate-reactive functional end groups, in particular hydroxyl groups, mercapto groups and / or amino groups. This reaction is carried out in the stoichiometric ratio of the isocyanate groups to the isocyanate-reactive functional end groups of 1: 1, or with a slight excess of isocyanate-reactive functional end groups, for example at temperatures of 20 ° C to 100 ° C, optionally with concomitant use of catalysts.

wobei R³, R⁵, R⁴ und a bereits vorhergehend beschrieben wurden.Suitable isocyanatosilane IS are compounds of the formula (VIII).

wherein R ³ , R ⁵ , R ⁴ and a have already been described above.

Examples of suitable isocyanatosilanes IS of the formula (VIII) are isocyanatomethyltrimethoxysilane, isocyanatomethyldimethoxymethylsilane 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyldimethoxymethylsilane, and their analogs having ethoxy or isopropoxy groups in place of the methoxy groups on the silicon.

The polymer preferably has hydroxyl groups as isocyanate-reactive functional end groups.

Polymers having hydroxyl groups are, on the one hand, polyols already mentioned, in particular high molecular weight polyoxyalkylene polyols, preferably polyoxypropylene diols having a degree of unsaturation lower than 0.02 meq / g and having a molecular weight in the range from 2000 to 30,000 g / mol, in particular those having a molecular weight in the range from 4000 to 30,000 g / mol.

On the other hand, hydroxyl-terminated, in particular hydroxyl-terminated, polyurethane polymers are also suitable for reaction with isocyanatosilanes IS of the formula (VIII). Such polyurethane polymers are obtainable by the reaction of at least one polyisocyanate with at least one polyol. This reaction can be carried out by reacting the polyol and the polyisocyanate with customary processes, for example at from 50 ° C. to 100 ° C., if appropriate with concomitant use of suitable catalysts, the polyol being metered in such a way that its hydroxyl groups in the Ratio to the isocyanate groups of the polyisocyanate in stoichiometric excess are present. Preference is given to a ratio of hydroxyl groups to isocyanate groups of from 1.3: 1 to 4: 1, in particular from 1.8: 1 to 3: 1.

Optionally, the polyurethane polymer can be prepared with the concomitant use of plasticizers, wherein the plasticizers used contain no isocyanate-reactive groups.

Suitable for this reaction are the same polyols and polyisocyanates already mentioned as being suitable for preparing an isocyanate group-containing polyurethane polymer used to prepare a silane-functional polyurethane polymer P1 .

For example, suitable silane-functional polymers P2 are commercially available under the trade names SPUR + ^® 1010LM, 1015LM and 1050MM from the Momentive Performance Materials Inc., USA, and sold under the trade name Geniosil ^® STP-E15, STP-10 and STP-E35 from Wacker Chemie AG, Germany.

In a third embodiment, the silane-functional polymer P is a silane-functional polymer P3 which is obtainable by a hydrosilylation reaction of polymers having terminal double bonds, for example poly (meth) acrylate polymers or polyether polymers, in particular allyl-terminated polyoxyalkylene polymers, described, for example, in US Pat US 3,971,751 and US 6,207,766 the entire disclosure of which is hereby incorporated by reference.

For example, suitable silane functional polymers P3 are commercially available under the tradenames MS Polymer ™ S203H, S303H, S227, S810, MA903 and S943, Silyl ™ SAX220, SAX350, SAX400 and SAX725, Silyl ™ SAT350 and SAT400, and XMAP ™ SA100S and SA310S from Kaneka Corp., Japan, and sold under the trade name Excestar ^® S2410, S2420, S3430, S3630, W2450 and MSX931 of Asahi Glass Co, Ltd., Japan.

Preferred silane-functional polymer P are silane-functional polymers P1 and silane-functional polyurethane polymers P3 .

Usually, the silane-functional polymer P in an amount of 5 to 50 wt .-%, in particular in an amount of 10 to 35 wt .-%, preferably 20 to 30 wt .-%, based on the total composition used.

• Mischen von mindestens einem härtbaren Strukturklebstoff mit mindestens einem silanfunktionellen Polymer;
• Vernetzen des silanfunktionellen Polymers in der Mischung zu einem Elastomer, wobei das Vernetzen des silanfunktionellen Polymers insbesondere durch Reaktion der Silangruppen mit Wasser erfolgt.

The composition according to the invention is typically obtainable by

• Mixing at least one curable structural adhesive with at least one silane-functional polymer;
• Crosslinking of the silane-functional polymer in the mixture to an elastomer, wherein the crosslinking of the silane-functional polymer is effected in particular by reaction of the silane groups with water.

In the preparation of the composition according to the invention, the curable structural adhesive is mixed with the silane-functional polymer, preferably until a homogeneous mixture is obtained. If the curable structural adhesive comprises a solid epoxy resin as epoxy resin A , mixing takes place at a temperature above the glass transition temperature Tg of the solid epoxy resin.

Wherever the curable structural adhesive to a curing epoxy resin composition, it can be mixed with the silane-functional polymer before the addition of the hardener B.

As a result, the temperature during mixing can be adjusted to or even above the curing temperature of the thermosetting epoxy resin composition, without resulting in curing of the structural adhesive. At higher temperatures, more efficient mixing is usually achieved.

After a particularly homogeneous mixture was obtained, the crosslinking of the silane-functional polymer takes place. The resulting elastomer is present in particular as a penetrating polymer network in the structural adhesive.

The crosslinking of the silane-functional polymer typically takes place by reaction of the silane groups with water.

The water for the crosslinking of the silane-functional polymer can be introduced or introduced into the composition in various ways. On the one hand, after mixing the curable structural adhesive with the silane-functional polymer, the composition can be left to stand under atmospheric conditions so that water in the form of atmospheric moisture enters the composition and leads to crosslinking of the silane-functional polymer.

On the other hand, when the curable structural adhesive is mixed with the silane functional polymer, water may be added to the composition in free or bound form. In bound form, water is usually bound to a support material or added, for example, in the form of an aqueous plastic dispersion.

For the crosslinking of the silane-functional polymer with water, the composition contains in particular at least one catalyst. Such catalysts are in particular organotin compounds, for example dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetylacetonate and dioctyltin diacetylacetonate; Titanates and zirconates, for example, tetraisobutoxy titanate and diisobutoxy titanium bis (ethylacetoacetate); Nitrogen compounds, especially tertiary amines, for example N, N-dimethylbenzylamine, N, N-dimethylcyclohexylamine and 1,4-diazabicyclo [2.2.2] octane, and amidines and guanidines, for example 1,8-diazabicyclo [5.4.0] undec-7 -en and 1,1,3,3-tetramethylguanidine; and mixtures of the catalysts mentioned.

It is essential for the composition according to the invention that it is designed as a shape memory material which has the highest possible dimensional stability in the temporary form and as complete a recovery as possible. Specifically, this means that the composition according to the invention can be kept in the temporary form for as long a period as possible, typically longer than 6 months, and that the composition, if required, by heating above the glass transition temperature Tg of the composition, completely their original form accept again. A sufficient resilience is typically given when a sample of a composition according to the invention with a height in the range of 5 to 10 mm is deformed in its height by 50% and can be reset to 60 to 100% of the original height if necessary.

• Erwärmen einer Zusammensetzung, wie sie vorhergehend beschrieben worden ist, auf eine Temperatur oberhalb ihrer Glasübergangstemperatur Tg;
• Verformen der Zusammensetzung, unter Spannung des chemisch vernetzten Elastomers auf der Basis eines silanfunktionellen Polymers;
• Abkühlen der verformten Zusammensetzung unter ihre Glasübergangstemperatur Tg.

In a further aspect, the present invention relates to a molded article which has been subjected to a reversible shaping, wherein the shaping comprises the steps:

• Heating a composition as described above to a temperature above its glass transition temperature Tg;
• Deforming the composition under tension of the chemically crosslinked elastomer based on a silane-functional polymer;
• Cooling the deformed composition below its glass transition temperature Tg.

FIG. 1 shows schematically the preparation of a novel molding of a composition based on an epoxy resin composition, as described above.

In this case, the solid composition 1 is in its original state Z1 in the original form, in which it was brought, for example, in their preparation. In a first step, the composition is then heated by a temperature ΔT ₁ to a temperature which is above its glass transition temperature Tg but, in the case of a thermosetting epoxy resin composition, below its curing temperature. If the composition is in this state Z2, it is brought into its temporary, yet deformable form 2 under the action of a force F. In this temporary, yet deformable form, as shown in state Z3, the chemically crosslinked elastomer is based on a silane-functional polymer in a taut form. The composition is maintained in this temporary form and the temperature of the composition is again lowered by the temperature ΔT ₁ to a temperature which is below its glass transition temperature Tg. In the process, the composition solidifies and is now firmly in its temporary form 3, as shown in state Z4. In this state as a shaped body, the composition is storage stable and can be further processed. Thus, the shaped body can be punched or cut and / or in particular attached to a carrier or arranged in a cavity to be reinforced of a structural component.

The deformation of the composition according to the invention, in which it is brought into its temporary form, is typically carried out by pressing, rolling, drawing and the like. When forming, it is important that the composition in the deformed state can be cooled to a temperature below its glass transition temperature Tg, so that it remains in its temporary form.

In a further aspect, the present invention relates to a reinforcing element for reinforcement in cavities of structural components comprising a support, to which a shaped body according to the above description is attached.

This carrier can consist of any materials. In particular, the carrier consists of a plastic, a metal or a combination of plastic and metal.

Preferred plastics are polyurethanes, polyamides, polyesters and polyolefins and polyolefin copolymers, in particular high-temperature-resistant polymers such as poly (phenylene ether), polysulfones or polyethersulfones. Most preferred plastics are polyamides (PA) such as PA6 or PA66, polyethylenes and polypropylene as well as polystyrene and copolymers such as acrylonitrile-butadiene-styrene (ABS). Preferred metals are aluminum, steel, nickel and alloys of these metals. The metal may further be untreated or it may be pretreated by suitable means, for example to prevent corrosion or to improve adhesion.

The carrier may further have any structure and structure. It may, for example, be solid, hollow or foamed or have a lattice-like structure. The surface of the carrier may typically be smooth, rough or textured.

In addition to its function as a carrier for the composition according to the invention or the molded part produced from it, the carrier can contribute to structural reinforcement or to sealing of the component or also to noise insulation.

The carrier may further comprise at least one fastening means, in particular a clip, for fastening and placing the reinforcing element in one Have cavity. The attachment of the reinforcing element with a clip is particularly suitable for applications in which the entire surface of the component, including the cavity inner wall, for example, must be accessible for dip coating. In such cases, an attachment, for example by gluing is not suitable because the paint can not reach the point of bonding.

Most preferably, the carrier consists of a plastic which is coated with a metal. As plastic and as metal, the materials described above are preferred.

The metal with which the plastic is coated, can be attached to the plastic in any way. For example, the attachment by mechanical fasteners such as nails, screws, rivets, mechanical clips, clamps, flanging and the like, or by gluing the metal to the plastic. Furthermore, the metal may also have been applied to the plastic by means of plastic electroplating. Most preferably, the layer thickness of the metal layer on the plastic carrier is 0.03 to 1.5 mm.

The plastic support, which is coated with a metal, has the advantage over a pure metal support that on the one hand it is lighter and on the other hand, by the properties of the plastic as the choice of material and its processing, in its mechanical properties and in its embodiment can be varied very wide. The advantage of the metal coating over a pure plastic carrier is that the metals are generally more adhesive. Another advantage of the metal coating is that with heat-curing structural adhesives, the metal layer can be heated very locally and efficiently by induction.

FIG. 2 shows a carrier 5 made of a plastic, which is coated with a metal 8. The metal is attached with nails 9 on the carrier. On the metal layer is a shaped body 3, consisting of a composition according to the invention in its temporary state.

FIG. 3 schematically shows a reinforcing element, consisting of a support 5, on which a molded body 3 of a composition according to the invention with thermosetting epoxy resin composition as a structural adhesive and chemically crosslinked elastomer based on a silane-functional polymer in its temporary form, is attached, in its initial state Z4. In a first step, the molded body 3 is then heated by a temperature ΔT ₁ to a temperature which is above the glass transition temperature Tg of the composition, whereby the elastomer is expanded on the basis of a silane-functional polymer and causes a deformation of the shaped body or composition 1 leads to its original shape. This corresponds to state Z5 in FIG FIG. 3 , Thereafter, the temperature is further increased by ΔT ₂ to a temperature at which the composition or curable structural adhesive cures. The cured composition 4 is shown in state Z6.

The increase in temperature, which leads to deformation of the molding, and the increase in temperature to cure the structural adhesive, do not necessarily have to run in two stages. It is quite possible, the two steps by a steady rise in temperature to run sequentially.

Furthermore, the invention includes the use of a reinforcing element, as previously described, for reinforcement in cavities of structural components. Such structural components are preferably used in bodies and / or frames of means of transport and locomotion, in particular of vehicles by water or on land or by aircraft. Preferably, the invention comprises the use of a reinforcing element according to the invention in the bodies or frames of automobiles, trucks, railway carriages, boats, ships, helicopters and aircraft, most preferably in automobiles.

• Platzieren eines Verstärkungselements gemäss vorhergehender Beschreibung in den Hohlraum eines strukturellen Bauteils;
• Erwärmen des Formkörpers 3 auf dem Verstärkungselement auf eine Temperatur oberhalb der Glasübergangstemperatur Tg der Zusammensetzung, wodurch der Formkörper in seine Form vor der Formgebung, also in die ursprüngliche Form, zurückgeht;
• Aushärten des härtbaren Strukturklebstoffs.

Another aspect of the present invention relates to a method for reinforcement in cavities of structural components comprising the steps:

• Placing a reinforcing element according to the above description in the cavity of a structural component;
• Heating the molded body 3 on the reinforcing member to a temperature above the glass transition temperature Tg of the composition, whereby the molded body is returned to its shape prior to molding, that is, to the original shape;
• Curing the curable structural adhesive.

In one embodiment of the described method for reinforcement in cavities of structural components, wherein the condition is that the support of the reinforcing element consists of an induction-heatable metal or of a material which is coated with an induction-heatable metal, and with the Provided that the curable structural adhesive is a thermosetting structural adhesive, the steps b ') and c') by induction, that is, by an alternating electromagnetic field of an induction coil, causes.

FIG. 4 shows analogously to FIG. 3 schematically, the reinforcement in a cavity of a structural member 6, wherein in the interior of the structural member, a reinforcing member consisting of a carrier 5 and a plurality of moldings 3 of a novel composition with thermosetting structural adhesive and chemically crosslinked elastomer based on a silane-functional polymer in its temporary form , is appropriate. The carrier of the reinforcing element is fastened with a clip 7 on the structural component. The molding or the composition is present in its temporary form (state Z4) and is subsequently heated by a temperature ΔT ₁ to a temperature which is above the glass transition temperature Tg of the composition. In this case, the elastomer relaxes on the basis of a silane-functional polymer and leads to a deformation of the molding or the composition 1 in its original shape, whereby the open gap 10 between the reinforcing element and cavity is closed and the inventive composition adheres to the cavity inner wall ( State Z5). After another temperature increase by a temperature .DELTA.T ₂ hardens the thermosetting structural adhesive. FIG. 4 , Condition Z6, shows the reinforced structural member with the cured composition 4.

FIG. 5 shows a reinforcing element, as it is used in a cavity 10 of a structural member 6 before the deformation of the molding or the inventive composition in its temporary shape 3, which is located on a support 5.

FIG. 6 shows the reinforcing element FIG. 5 as it is used in a cavity of a structural member 6, wherein the molding or the inventive composition in this case has already returned to its original shape and adheres to the inner walls of the structural member 6. Further shows FIG. 6 the cured composition 4. The shape and structure of reinforcing elements according to the invention can be chosen according to their place of use.

Furthermore, the present invention relates to a cured composition as obtainable by a curing process, in particular by heat curing, from a previously described composition.

Examples

In the following, exemplary embodiments are listed which are intended to explain the described invention in more detail. Of course, the invention is not limited to these described embodiments.

test method

The dimensional stability of the material in the temporary mold was determined during 7 days at standard climate (23 ° C / 50% humidity) (" Relaxation "), the resilience to the original form after 7 days of storage under standard conditions. The dimensions of the original shape of the specimens measures 10x10x6 mm (LxWxH). The height in original form ( H ₀ ) was thus 6 mm. By pressing at elevated temperature and subsequent cooling, the specimens were in the temporary shape with a height of 3 mm brought ( H _Temp ), which corresponds to a compression of 50% and thus allows the recovery process a gain in altitude of 100%.

The relaxation is defined here as: $$\mathit{relaxation}\left[\mathit{\%}\right]\mathit{=}\frac{{\mathit{H}}_{\mathit{Temp}}\left(\mathit{Day}\mathit{7}\right)\mathit{-}{\mathit{H}}_{\mathit{Temp}}\left(\mathit{Day}\mathit{0}\right)}{{\mathit{H}}_{\mathit{Temp}}\left(\mathit{Day}\mathit{0}\right)}\cdot \mathit{100}$$

The resilience is determined as: $$\mathit{R}\ddot{\mathit{u}}\mathit{ckstellverm}\ddot{\mathit{O}}\mathit{gene}\left[\mathit{\%}\right]\mathit{=}\frac{{\mathit{H}}_{\mathit{0}}\left(\mathit{Day}\mathit{7}\mathit{.}\mathit{after\; Aush}\ddot{\mathit{a}}\mathit{Maintenance}\right)\mathit{-}{\mathit{H}}_{\mathit{Temp}}\left(\mathit{Day}\mathit{7}\right)}{{\mathit{H}}_{\mathit{0}}\left(\mathit{Day}\mathit{0}\right)\mathit{-}{\mathit{H}}_{\mathit{Temp}}\left(\mathit{Day}\mathit{0}\right)}\mathit{\cdot }\mathit{100}$$

Preparation of N- (3-trimethoxysilyl-propyl) -amino-succinic acid diethyl ester

To 179 g (1 mol) 3-aminopropyl-trimethoxysilane (Silquest ^® A-1110 from Momentive Performance Materials) were exclusion of moisture, 172 g (1 mol) of diethyl maleate were added dropwise slowly with good stirring, and then further stirred for 2 hours. There was obtained a colorless liquid having a viscosity at 20 ° C of 60 mPa · s.

Preparation of silane-functional polymer P1

Absence of moisture, 1000 g of polyol Acclaim ^® 12200 (from Bayer; low monol polyoxypropylene diol, OH number 11.0 mg KOH / g, water content approximately 0.02 wt .-%), 43.6 g of isophorone diisocyanate (Vestanat ^® IPDI from Degussa) and 0.12g of dibutyltin dilaurate heated with constant stirring to 90 ° C and left at this temperature until the titrimetrically determined content of free isocyanate groups had reached a value of 0.7 wt .-%. Subsequently, 62.3 g of diethyl N- (3-trimethoxysilyl-propyl) -amino-suberate were mixed in and the mixture was stirred at 90 ° C. until no free isocyanate was detected by FT-IR spectroscopy. The silane functional polyurethane polymer was cooled to room temperature and stored with exclusion of moisture.

Preparation of the specimens

Formulations 1 to 7 were made by mixing the ingredients according to Table 1 in the corresponding weight percent by means of corotating Twin-screw extruder manufactured at 90 ° C melting temperature.

The formulations thus prepared were then processed into plates of 6 mm thickness. Subsequently, the respective silane-functional polymer was chemically crosslinked for at least 1 week at room temperature and 50% humidity. Specimens in their original form measuring 10x10x6 mm were subsequently cut out of the plates. Table 1 Formulation <b><i> 1 </ i></b> to <b><i> 7 </ i></b> in wt% and results; 1 2 3 4 5 6 7 Araldite ^® GT 7004 ^a) 62.9 46.7 62.9 46.7 60.4 50.3 46.7 dicyandiamide 1.4 1.1 1.4 1.1 1.4 1.1 1.1 MS S203H ^b) 31.5 46.8 MS S303H ^b) 31.5 46.8 SAX 260 ^b) 30.1 40.1 P1 46.8 Metatin K740 ^{® c)} 1.13 1.13 1.13 1.13 1.13 1.13 1.13 DBU ^d) 12:57 12:57 12:57 12:57 12:57 12:57 12:57 Purmol ^® 13 ^s) 1.6 2.3 1.6 2.3 1.6 2 2.3 Aerosil® ^f) 0.9 1.4 0.9 1.4 1.4 ^HDK® H18 ^f) 4.8 4.8 Relaxation [%] 0 0 0 0 0 0 0 Resilience [%] 97 98 67 95 65 71 95 ^a) available from Huntsman Advanced Materials;
^b) available from Kaneka Corp .;
^c) 10% solution in DIDP available from Rohm &Haas;
^d) 1,8-diazabicyclo [5.4.0] undec-7-ene, 50% in DIDP, available from Fluka;
^e) available from Zeochem AG;
^f) fumed silica, available from Wacker Chemie AG.

LIST OF REFERENCE NUMBERS

1

Composition in the original form

2

Composition (deformable)

3

Shaped body (temporary shape)

4

Cured composition

5

carrier

6

structural component

7

clip

8th

metal layer

9

nail

10

gap

Z1

Condition of the composition in original form

Z2

Condition of the deformable composition

Z3

Condition of the composition in the temporary state (shaped body)

Z4

Condition of the cured composition

ΔT ₁

Temperature difference between temperature below Tg of the composition and temperature above the Tg of the composition

ΔT ₂

Temperature difference between temperature above Tg of the composition and the curing temperature of the composition

Claims (12)

Comprising composition - At least one curable structural adhesive; such as - At least one chemically crosslinked elastomer based on a silane-functional polymer. A composition according to claim 1, characterized in that the chemically crosslinked elastomer is present as a penetrating polymer network in the structural adhesive. Composition according to one of claims 1 or 2, characterized in that the silane-functional polymer is obtainable by reacting a silane having at least one isocyanate-reactive group with a polyurethane polymer having isocyanate groups; by the reaction of an isocyanatosilane with a polymer having isocyanate-reactive functional end groups; or by a hydrosilylation reaction of polymers having terminal double bonds. Composition according to one of the preceding claims, characterized in that the curable structural adhesive is a thermosetting epoxy resin composition comprising at least one epoxy resin A and at least one curing agent B for epoxy resins, which is activated by elevated temperature. Composition according to any one of the preceding claims, obtainable by Mixing at least one curable structural adhesive with at least one silane-functional polymer; - Crosslinking of the silane-functional polymer in the mixture to an elastomer. A composition according to claim 5, characterized in that the crosslinking of the silane-functional polymer takes place by reaction of the silane groups with water. Composition according to one of the preceding claims, characterized in that the proportion of curable structural adhesive 50 to 95 wt .-% and the proportion of chemically crosslinked elastomer based on a silane-functional polymer is 5 to 50 wt .-%, each based on the total composition , Process for the preparation of a composition according to claim 1 comprising the steps: - mixing the curable structural adhesive with a silane-functional polymer; and - Crosslinking of the silane-functional polymer in the mixture to an elastomer. A process according to claim 8, characterized in that the crosslinking of the silane-functional polymer takes place by reaction of the silane groups with water. Shaped body (3), characterized in that it has been subjected to a reversible shaping, wherein the shaping comprises the steps - heating a composition according to any one of claims 1 to 7 to a temperature above its glass transition temperature Tg; - deforming the composition, under tension of the chemically crosslinked elastomer based on a silane-functional polymer; Cooling the deformed composition below its glass transition temperature Tg. Reinforcing element for reinforcement in cavities of structural components comprising a support (5) to which a shaped body (3) according to claim 10 is attached. Reinforcing element according to claim 11, characterized in that the carrier (5) consists of a plastic which is coated with a metal.

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